The present invention relates to an on-line system, and more particularly to an on-line system having a plurality of terminal equipments and host computers connected to the terminal equipments and mainly executing regular jobs, wherein the system can efficiently execute irregular jobs as well as regular jobs requested by a terminal equipment.
A conventional on-line system has a plurality of host computers and terminal equipments connected to the host computers which execute jobs requested by the terminal computers. In such an on-line system, a job (process) request from a terminal computer includes a regular job request and an irregular job request. A transaction processing system has been adopted for executing a regular job. In a transaction processing system, a host computer processes a regular job in units of transaction data sent from a terminal equipment, in a fixed manner within a space (virtual address space) with predefined emvironments. The transaction processing system which processes a regular job in units of transaction and in a fixed manner is suitable for a regular job such as automatic cash accounting in a banking system, but it is not suitable for an irregular job.
An interactive processing system such as a Time Sharing System (TSS) has been adopted in an on-line system for executing an irregular job. In an interactive processing system, upon an irregular job request from a terminal equipment by a user, a new space (virtual address space) is generated to analyze the job request by using the space, to thereby select suitable programs and files, and perform other necessary processes. After predefining such necessary environments, the selected programs are made to run for execution of the given irregular job.
Such a time sharing system is suitable for an irregular job because after the necessary environments are predefined and suitable programs are selected to provide a job execution process, the given job is executed. However, each time an irregular job request is made by a user, a new virtual address space must be generated to prepare necessary environments and select necessary programs to predefine a job execution process. Thus, the overhead of processing becomes large and a large load is applied to a host computer.
It is therefore preferable to adopt the transaction processing system for execution of a regular job such as automatic cash accounting in a banking system, and the time sharing system for an irregular job, in order to reduce a load on a host computer.
A conventional terminal equipment has not been provided with an intelligence function so that it displays information sent from a host computer as it is, and sends information to the host computer in a format as requested by the host computer. The functions of a terminal equipment have been determined in accordance with the types of regular or irregular jobs the host computers execute. Thus, each terminal equipment has its specific function which is determined based on the type of jobs it requests to the host computer, and it has not been considered that a single terminal equipment is used for both regular and irregular jobs. For example, in "Guide to Information Processing System", at pp. 65 to 70, sixth Edition published on Apr. 10, 1980 by The Institute of Electrical Engineers of Japan, there are shown various types of on-line real time systems including an information retrieval system such as an on-line banking system and a shared use system such as a time sharing system. However, these systems are used independently and separately and the above document does not teach that the same terminal equipment is used for both systems.
With the advent of a terminal equipment having an intelligence function, however, it has become possible, for example, for a terminal equipment to process information from a host computer to some degree and display it, send information inputted by a user to the host computer by changing the information in a format suitable for the host computer. Thus, the same terminal equipment can be used for both regular and irregular jobs.
In the transaction processing system for executing a regular job, there is no specific interconnection between a terminal equipment and a job execution process (or virtual address space) within a host computer. Therefore, a single job execution process is commonly used by a number of terminal equipments, resulting in alleviating a load on a host computer and in facilitating user operation associated with job request.
In contrast with the above, in the interactive processing system such as a time sharing system, upon a job request from a terminal equipment, a virtual address space is generated in a host computer to prepare a job execution process therein.
Accordingly, if the same terminal equipment is used for an irregular job in a system which mainly executes regular jobs, the following problems occur. Namely, each time a job request is made by a user, a virtual address space must be generated and other necessary processes must be performed, resulting in a large load on a host computer and a cumbersome user operation associated with an irregular job request.